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Theorem dfrals2 50625
Description: The bounded "all some" form is the general form with the class membership folded into the antecedent. (Contributed by David A. Wheeler, 22-Oct-2018.) (Revised by David A. Wheeler, 12-Jul-2026.)
Assertion
Ref Expression
dfrals2 (∀∃𝑥𝐴(𝜑𝜓) ↔ ∀∃𝑥((𝑥𝐴𝜑) → 𝜓))

Proof of Theorem dfrals2
StepHypRef Expression
1 df-ral 3082 . . . 4 (∀𝑥𝐴 (𝜑𝜓) ↔ ∀𝑥(𝑥𝐴 → (𝜑𝜓)))
2 impexp 456 . . . . 5 (((𝑥𝐴𝜑) → 𝜓) ↔ (𝑥𝐴 → (𝜑𝜓)))
32albii 1852 . . . 4 (∀𝑥((𝑥𝐴𝜑) → 𝜓) ↔ ∀𝑥(𝑥𝐴 → (𝜑𝜓)))
41, 3bitr4i 281 . . 3 (∀𝑥𝐴 (𝜑𝜓) ↔ ∀𝑥((𝑥𝐴𝜑) → 𝜓))
5 df-rex 3092 . . 3 (∃𝑥𝐴 𝜑 ↔ ∃𝑥(𝑥𝐴𝜑))
64, 5anbi12i 640 . 2 ((∀𝑥𝐴 (𝜑𝜓) ∧ ∃𝑥𝐴 𝜑) ↔ (∀𝑥((𝑥𝐴𝜑) → 𝜓) ∧ ∃𝑥(𝑥𝐴𝜑)))
7 df-rals 50624 . 2 (∀∃𝑥𝐴(𝜑𝜓) ↔ (∀𝑥𝐴 (𝜑𝜓) ∧ ∃𝑥𝐴 𝜑))
8 df-als 50623 . 2 (∀∃𝑥((𝑥𝐴𝜑) → 𝜓) ↔ (∀𝑥((𝑥𝐴𝜑) → 𝜓) ∧ ∃𝑥(𝑥𝐴𝜑)))
96, 7, 83bitr4i 306 1 (∀∃𝑥𝐴(𝜑𝜓) ↔ ∀∃𝑥((𝑥𝐴𝜑) → 𝜓))
Colors of variables:    wff setvar class
This proof depends on syntax axioms:  wi 4  wb 209  wa 401  wal 1568  wex 1812  wcel 2146  wral 3081  wrex 3091  ∀∃wals 50621  ∀∃wrals 50622
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842
This proof depends on definitions:  df-bi 210  df-an 402  df-ral 3082  df-rex 3092  df-als 50623  df-rals 50624
This theorem is used by:  rals-no-surprise  50642
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